This invention relates to a fence for enclosing impurities floating on water.
Previously hereto, U.S. Pat. No. 4,248,547 was issued which patent described and claimed a two-ply fence for enclosing impurities on water with the two plies fused together in substantial areas and with weighted floating pickets located between the two plies. Rings were located at both ends of all of the pickets with one rope extending through rings affixed at the upper ends of the pickets and another rope extending through the rings at the lower ends of the pickets. Two other ropes extended through the plies and around the pickets.
The earlier fence described and claimed in U.S. Pat. No. 4,248,542 was and still is a substantial improvement over the prior art then known in that it provided an economical fence and especially a fence which can be readily rolled for storage and transporting. However, further economy in production of the fence and ease of handling has been achieved by the present invention.
Since in the present invention two plies of material are fused in a planned pattern with only a limited portion of the two plies being fused together, a wide range of coated fabrics may be used. The continued repetition of a fixed pattern of fusing can also be readily provided by changing the positions of fusing elements, rather than the redesign and repreparation of templates as was required by the earlier invention.
Another problem with the earlier fence, as well as other existing fences, is that in connecting the corresponding ends of two adjoining bands, which are sections of the fence, together, a substantial problem of leakage often does result. For convenience of handling bands must be constructed only to a limited length, usually about fifty feet, and therefore several bands must be connected end to end in order to contain the impurities. Prior to this invention, each such end to end connection frequently would lack the impervious quality of the fence itself, thus providing for leakage of impurities outside of the enclosure provided by the fence. In the alternative, where positive connection has been provided, earlier designs required expensive interlocking parts usually heavy and difficult to handle.
The benefits of improved function and exceptional economy of production as well as ease of handling are provided by this invention, along with exceptional prevention of leakage at the connection between the bands.